# Camera Coordinate System and Conventions¶

## Camera¶

The pose of a camera, conceptually, consists of two things:

1. Which direction does it face in, i.e. its local coordinate axes

2. Where is it, i.e. the position of the camera origin

### Local coordinate system of camera¶

These online docs say that, from the POV of a camera (a.k.a. a Shot object):

• The z-axis points forward

• The y-axis points down

• The x-axis points to the right

In the 3D reconstruction viewer, the axes go Red, Green, Blue: x, y, z.

The OpenSfM Pose class contains a rotation field, representing the local coordinate system as an axis-angle vector.

• The direction of this 3D vector represents the axis around which to rotate.

• The length of this vector is the angle to rotate around said axis. It is in radians.

### Camera position¶

To get and/or set the actual the actual camera position in world coordinate, one has to use get_origin()/set_origin().